test.each

[mbrevda]

What is the problem this feature will solve?

Allows for duplicating the same test with different data

What is the feature you are proposing to solve the problem?

test.each(list), which does a forEach on the list and runs the test once for each item

What alternatives have you considered?

Manually doing a for each. This has the drawback of more boilerplate

Prior art:
https://jestjs.io/docs/api#testeachtablename-fn-timeout
https://www.npmjs.com/package/mocha-each

[cjihrig]

Can you clarify the "less pretty test names" and "requires more explicit exception handling" points?

[RedYetiDev]

(Didn't mean to self-assign)

[mbrevda]

Sure. The signature for

Can you clarify the "less pretty test names" and "requires more explicit exception handling" points?

reviewing my current code I didn't find anything to backup those claims (I've since removed them from my post). Instead, here is an illustration of the difference. This can be currently done like:

[].forEach((i) => {
  describe(`with ${i} `, async () => {
    [].forEach((j) => {
      it(`with id ${j}`, async () => {
        assert.ok(() => true);
      });
    });
  });
});

vs how it might be done with a native support:

describe.each([])("with %i", (i) => {
  it.each([])("with id %i", async (j) => {
    assert.ok(() => true);
  });
});

[RedYetiDev]

Looking at it now, it seems to only be a few more lines to implement in userland rather than in core (though initially I did suggest adding this).

[trivikr]

Similar request for reference #47902